Do people really think this looks SO MUCH better?
(I know this is not the main area but its the same other than the live feed and ads on the right)
In my theory, I believe its due to the cool thumbnails of World War Z, Ryse, Skype, etc. They stimulate our brains perhaps, like dopamine. Remove those and you have a bunch of green squares.
The facts are: If you want to get to your friends, you leave to a different page/tab/app. On the PS4 UI, you scroll, and it instantly shows your list, similar to the PS3. Same with Messages on X1, you must leave to a new tab. Again, they look to be instant after scrolling to 'messages' on the PS4 (from the looks of it).
The Sharing UI is nicer on the X1 because you dont have to go to a new page like the Ps4. However, the ps4 has longer capturing and has a sharing button on the controller so their convenience is tied, IMO.
The dynamic menus on the Ps4 UI is a good feature too if used wisely by devs. Hopefully they aren't slow to load like the video or else it loses points.
I do like the features of viewing # of players in top games and the 'following' feature on the X1.